The goal of the clinical investigative core is to accomplish meaningful clinical investigative research while at the same time integrating the highest quality 'state of the art' patient care. The function of the core will be to provide clinical, technical expertise and appropriate facilities to help implement the three clinical protocols of this program project. Many of the tests, investigations, and gathering of data will occur at a time when the patient is the least stable and most care is required. This core centralizes the investigative team which will remain on 24-hour call throughout the year and provide the expertise necessary to carry out the studies involving cerebral microdialysis, cerebral blood flow, magnetic resonance brain water imaging and intracranial pressure dynamics. The clinical research team, will include a neurosurgical head injury fellow, trained at MCV in all aspects of head injury management, who will assume responsibility for coordinating the studies with ongoing patient care. Each clinical research fellow will be assigned one of three clinical projects and serve as back up for the remaining two. Expertise in neuroradiology for scheduling and on-site conduct of imaging procedures, and technical refinement CTCBF, CTCBV, and MRI methods will also be provided by the Core. In addition, the core will provide access to the Neurosurgical computing center for on-line computer monitoring of all physiologic parameters monitored in the ICU as well as data management expertise to analyze data essential to all clinical projects.